Perennial pepperweed is the common name for Lepidium latifolium, an aggressive non-native plant of the mustard family. Pepperweed poses a significant threat to habitat quality and once a population is established, pepperweed creates dense, single-species stands, out-competing local flora.

NHCP has been monitoring for pepperweed in coastal NH for the last decade. Six pepperweed sites are being managed by NHCP in the towns of Seabrook, Hampton, North Hampton, Rye, and Newcastle.

Pepperweed has been found growing in salt marsh edges, along roadsides, and in drainage ditches in Newburyport, Mass., and the islands of Boston Harbor, and is spreading northward. This plant is of particular concern because it is able to spread not only through seed production, but also through extensive creeping root systems.

The mature plant generally grows 1 to 3 feet tall, but can reach up to 4 feet in height. The alternate, waxy, lance shaped leaves have smooth or toothed margins and a distinctive white mid-vein. Pepperweed flowers in July, producing small white flowers in dense clusters.

Pepperweed Patrol

The Pepperweed Patrol is a volunteer effort to find and eradicate this invader before it becomes a problem. The goal of the pepperweed patrol is early detection, rapid response!

Populations of pepperweed in NH have been located in Seabrook, Hampton, North Hampton, Rye, and Newcastle. The Coastal Program needs help finding the locations of new infestations. For more information or to report a sighting, please contact the Coastal Program at (603) 559-1500.

Please do not attempt to remove the plant yourself. Pepperweed requires specific handling techniques to prevent further spreading.